Urban water takes inspiration from nature

Drawing inspiration from nature to manage the urban water cycle

Nature is magnificent and a source of creativity, helping us to strengthen the circular economy and protect urban water, writes Marc Simon.

The industrial era was a turning point where humans exploited limited natural resources on a massive scale. This was unwise behaviour, especially given our reliance on nature to survive, including in our urban environments.

Despite this complacency, and at a time when we need to more than ever, we can protect our urban environment by learning from the natural cycles all around us. This circular economy should lie in the very heart of environmental services: turning one person’s waste into another’s asset.

So, let’s look at how the living world is a source of inspiration for our water and waste management or our air treatment activities.

Understanding urban water

Water is the primary component of living matter. It is a quasi-universal solvent and, therefore, a matrix of biochemical reactions. In this respect, it is also a marker of human activities.

The urban water cycle comprises different stages, from the drawing of raw water from natural environments to the production and distribution of drinking water. It’s also used for domestic and industrial purposes, followed by the collection and treatment of wastewater, which is returned to the natural ecosystem.

In this cycle, the treatment in wastewater treatment plants is based on biological processes that use the action of bacteria to convert the dissolved polluting particles into solid pollution. This process results in the release of clean water into the natural environment and the production of an organic mass of bacteria and suspended solids.

However, this process consumes much energy, in particular, to produce nitrates before the formation of gaseous nitrogen.

We have developed an innovative biological treatment technology called the Cleargreen process. This consumes significantly less energy than conventional treatments and increases the production of biogas by favouring the development of a bacterium capable of transforming the nitrites directly into gaseous nitrogen, without producing any nitrates.

The methanation of sewage sludge is another example of how nature inspires the water cycle. This process consists of using the properties of anaerobic bacteria to produce biogas, which is purified into biomethane, then injected into the urban natural gas network.

In nature, the notion of waste does not exist. The “waste” produced by one organism is useful to another.

Finally, we also develop bio-inspired solutions for wastewater discharges that speed up the restoration of marine biodiversity. The REFISH project is being tested in one of the ports in the harbour of Marseilles, consists of installing artificial habitats inspired by marine posidonia beds that are conducive to the development of young fish.

Breeding flies to transform biowaste

In nature, the notion of waste does not exist. The “waste” produced by one organism is useful to another. This is the logic behind the circular economy, as demonstrated by the initiative launched by the start-up Nextalim.

This Poitiers-based company has developed know-how in the breeding of flies that transform biowaste into proteins for the animal feed and green chemistry sectors. This solution combats food waste by creating a new channel for the recovery of organic waste and also offers a source of alternative proteins.

Considering the world is predicted to have 11 billion inhabitants by 2011, this is a significant development! For example, this insect flour can be used in fish farming, which currently consumes between 2.5 and 5 kg of wild fish to produce 1 kg of farmed fish. It represents a solution for the future, in particular in the fight against over-fishing.

Along the same lines as the circular economy, the industrial ecology aims to create flows between different uses.

For example, in Bessières, near Toulouse, we recover the heat produced by the combustion of household waste to heat tomato greenhouses. In Narbonne, the Bioresource Lab, an offshoot of the CIRSEE that will open in 2020, plans to develop processes to extract high added-value molecules from organic waste.

Packaging’s role in protecting and transporting is a biomimetic application of a fruit that protects its seeds.

Finally, circularity starts in the product design phase, especially of packaging. Packaging's role to protect and transport its content is a biomimetic application of a fruit that protects its seeds.

However, unlike aluminium or plastic packaging materials, fruit is produced and decomposes at atmospheric pressures and temperatures, without consuming any fossil energy. In this respect, the ecodesign of packaging for easy recycling has become a vital issue, on which we are working with our industrial customers.

Using micro-algae to purify the air

According to the WHO, 91 per cent of the world’s population breathes polluted air. In France, 90 per cent of the people of Greater Paris is exposed to atmospheric pollution, and 65 per cent of them consider air quality to be their most pressing environmental concern.

Here again, the living world is a source of inspiration for innovative processes to address this significant environmental and public health issue. With Fermentalg, we have developed a solution that uses the properties of micro-algae to purify the air.

The French National Institute for Industrial Environment and Risks (INERIS) has certified our first tests on cases of atmospheric pollution representative of the world's megacities. For example, where fine particles were cut by 66 per cent to 99 per cent and nitrogen oxides were reduced by 76 per cent to 97 per cent, depending on the configuration.

These concrete examples illustrate how the numerous faculties of the living world inspire the implementation of the circular economy in the solid (waste), liquid (water) and gaseous (air) phases.

The collaborative nature of the innovation process itself inevitably draws inspiration from ecological principles. But, we must not reduce biomimicry to a “library” of physical and chemical principles. First and foremost, nature is a source of wonder, nature is magnificent, and this beauty is a source of creativity and innovation in itself!